An anomaly opens a portal which brings three people from different time periods under one roof to deal with the alien race that monitors the universe for inferior race development.

Three strangers brought together from different time period ?have 24 hours to convince an alien race that humanity is worthy of being saved.

Thank you all for the feedback. I'll rewrite the logline?using the advice received and I will post it again.

You haven't told us what the aliens want, What are the stakes?
Also, what is the actual goal of the protagonist (s)??